Analysis of xx-top500-074-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .2.7...1........3........9....12.6..9...8....3.....4...1.2..5..4....3............ initial

Autosolve

position: .2973.8148..9.123.13.8.279....129683962384157381...429.1329.5484.8.139.229.4.83.1 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C2: 5,6 => CTR => C2: 4,7
* PRF # F6: 5,6 => SOL
* DIS # F6: 7 => CTR => F6: 5,6
* DIS # C2: 5,6 => CTR => C2: 4,7
* DIS # E6: 5,6 => CTR => E6: 7
* PRF # E6: 7 => SOL
* PRF # F6: 5,6 => SOL
* DIS # F6: 7 => CTR => F6: 5,6
* DIS # C9: 6,7 => CTR => C9: 5
* PRF # C9: 5 => SOL
* PRF # C9: 5,7 => SOL
* DIS # C9: 6 => CTR => C9: 5,7
* PRF # E9: 6,7 => SOL
* DIS # E9: 5 => CTR => E9: 6,7
* DIS # F6: 6,7 => CTR => F6: 5
* PRF # F6: 5 => SOL
* PRF # E9: 5,6 => SOL
* DIS # E9: 7 => CTR => E9: 5,6
* DIS # C9: 6,7 => CTR => C9: 5
* PRF # C9: 5 => SOL
* PRF # E9: 6,7 => SOL
* DIS # E9: 5 => CTR => E9: 6,7
* CNT  22 HDP CHAINS /  34 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* DIS # C2: 5,6 => CTR => C2: 4,7
* DIS C2: 4,7 # C3: 4 => CTR => C3: 5,6
* PRF C2: 4,7 + C3: 5,6 # F6: 5,6 => SOL
* STA C2: 4,7 + C3: 5,6 + F6: 5,6
* CNT   3 HDP CHAINS /   5 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Details

Positions

.2.7...1........3........9....12.6..9...8....3.....4...1.2..5..4....3............ initial
.2973.8148..9.123.13.8.279....129683962384157381...429.1329.5484.8.139.229.4.83.1 autosolve
529736814847951236136842795754129683962384157381675429613297548478513962295468371 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
A1: 5,6
F1: 5,6
I2: 5,6
I3: 5,6
A4: 5,7
D6: 5,6
A7: 6,7
B8: 5,7
F7: 6,7
D8: 5,6
H8: 6,7
H9: 6,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E2,E3: 4.. / E2 = 4  => 15 pairs (_) / E3 = 4  => 16 pairs (_)
B4,C4: 4.. / B4 = 4  => 14 pairs (_) / C4 = 4  => 16 pairs (_)
C3,E3: 4.. / C3 = 4  => 15 pairs (_) / E3 = 4  => 16 pairs (_)
B2,B4: 4.. / B2 = 4  => 16 pairs (_) / B4 = 4  => 14 pairs (_)
I2,I3: 5.. / I2 = 5  => 14 pairs (_) / I3 = 5  => 13 pairs (_)
B8,C9: 5.. / B8 = 5  =>  0 pairs (X) / C9 = 5  =>  0 pairs (_)
D8,E9: 5.. / D8 = 5  =>  0 pairs (*) / E9 = 5  =>  0 pairs (X)
A1,F1: 5.. / A1 = 5  =>  0 pairs (*) / F1 = 5  =>  0 pairs (X)
B8,D8: 5.. / B8 = 5  =>  0 pairs (X) / D8 = 5  =>  0 pairs (_)
C9,E9: 5.. / C9 = 5  =>  0 pairs (*) / E9 = 5  =>  0 pairs (X)
A1,A4: 5.. / A1 = 5  =>  0 pairs (*) / A4 = 5  =>  0 pairs (X)
D6,D8: 5.. / D6 = 5  =>  0 pairs (X) / D8 = 5  =>  0 pairs (_)
F1,F6: 5.. / F1 = 5  =>  0 pairs (X) / F6 = 5  =>  0 pairs (_)
I2,I3: 6.. / I2 = 6  => 13 pairs (_) / I3 = 6  => 14 pairs (_)
A7,C9: 6.. / A7 = 6  =>  0 pairs (*) / C9 = 6  =>  0 pairs (X)
H8,H9: 6.. / H8 = 6  =>  0 pairs (*) / H9 = 6  =>  0 pairs (X)
A1,F1: 6.. / A1 = 6  =>  0 pairs (X) / F1 = 6  =>  0 pairs (_)
A7,F7: 6.. / A7 = 6  =>  0 pairs (*) / F7 = 6  =>  0 pairs (X)
D8,H8: 6.. / D8 = 6  =>  0 pairs (X) / H8 = 6  =>  0 pairs (_)
A1,A7: 6.. / A1 = 6  =>  0 pairs (X) / A7 = 6  =>  0 pairs (_)
D6,D8: 6.. / D6 = 6  =>  0 pairs (*) / D8 = 6  =>  0 pairs (X)
B2,C2: 7.. / B2 = 7  =>  0 pairs (X) / C2 = 7  => 15 pairs (_)
E6,F6: 7.. / E6 = 7  =>  0 pairs (*) / F6 = 7  =>  0 pairs (X)
F7,E9: 7.. / F7 = 7  =>  0 pairs (*) / E9 = 7  =>  0 pairs (X)
H8,H9: 7.. / H8 = 7  =>  0 pairs (X) / H9 = 7  =>  0 pairs (_)
A7,F7: 7.. / A7 = 7  =>  0 pairs (X) / F7 = 7  =>  0 pairs (_)
B8,H8: 7.. / B8 = 7  =>  0 pairs (*) / H8 = 7  =>  0 pairs (X)
A4,A7: 7.. / A4 = 7  =>  0 pairs (*) / A7 = 7  =>  0 pairs (X)
E6,E9: 7.. / E6 = 7  =>  0 pairs (*) / E9 = 7  =>  0 pairs (X)
F6,F7: 7.. / F6 = 7  =>  0 pairs (X) / F7 = 7  =>  0 pairs (_)
* DURATION: 0:00:58.125048  START: 05:14:35.596659  END: 05:15:33.721707 2017-05-04
* CP COUNT: (30)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,A7,B8,D6,D8,F1,F7,H8,H9,I2,I3)
* .2973.8148..9.123.13.8.279....129683962384157381...429.1329.5484.8.139.229.4.83.1
* PAIR A1: 5,6 BLK 1
C2: 5,6,4,7                              # reduction candidate for 5,6
C2: 5,6 => CTR
* .2973581487.94123.1348.279..4.129683962384157381...429.1329.54845861397229.458361
C2: 4,7                                  # 13 pairs
C3: 5,6,4                                # reduction candidate for 5,6
C3: 5,6                                  # 16 pairs
* PAIR F1: 5,6 BLK 2
E2: 5,6,4                                # reduction candidate for 5,6
E2: 5,6                                  # 16 pairs
E3: 5,6,4                                # reduction candidate for 5,6
E3: 5,6                                  # 15 pairs
* PAIR F1: 5,6 COL F
F6: 5,6,7                                # reduction candidate for 5,6
F6: 5,6 => SOLVED
* 529736814847951236136842795754129683962384157381675429613297548478513962295468371
F6: 7 => CTR
* .297358148..9.123.13.8.279.5..129683962384157381..7429713296548458.139.229.4.83.1
* PAIR I2: 5,6 ROW 2
C2: 5,6,4,7                              # reduction candidate for 5,6
C2: 5,6 => CTR
* .2973581487.94123.1348.279..4.129683962384157381...429.1329.54845861397229.458361
C2: 4,7                                  # 13 pairs
E2: 5,6,4                                # reduction candidate for 5,6
E2: 5,6                                  # 16 pairs
* PAIR I3: 5,6 ROW 3
C3: 5,6,4                                # reduction candidate for 5,6
C3: 5,6                                  # 16 pairs
E3: 5,6,4                                # reduction candidate for 5,6
E3: 5,6                                  # 15 pairs
* PAIR A4: 5,7 BLK 4
B4: 5,7,4                                # reduction candidate for 5,7
B4: 5,7                                  # 16 pairs
C4: 5,7,4                                # reduction candidate for 5,7
C4: 5,7                                  # 14 pairs
* PAIR D6: 5,6 BLK 5
E6: 5,6,7                                # reduction candidate for 5,6
E6: 5,6 => CTR
* .2973.8148..9.123.13.8.279....129683962384157381..7429713296548458.139.229.4.83.1
E6: 7 => SOLVED
* 529736814847951236136842795754129683962384157381675429613297548478513962295468371
F6: 5,6,7                                # reduction candidate for 5,6
F6: 5,6 => SOLVED
* 529736814847951236136842795754129683962384157381675429613297548478513962295468371
F6: 7 => CTR
* .297358148..9.123.13.8.279.5..129683962384157381..7429713296548458.139.229.4.83.1
* PAIR A7: 6,7 BLK 7
C9: 6,7,5                                # reduction candidate for 6,7
C9: 6,7 => CTR
* .297358148..9.123.13.8.279.5..129683962384157381576429.1329.54845861397229.458361
C9: 5 => SOLVED
* 529736814847951236136842795754129683962384157381675429613297548478513962295468371
* PAIR B8: 5,7 BLK 7
C9: 5,7,6                                # reduction candidate for 5,7
C9: 5,7 => SOLVED
* 529736814847951236136842795754129683962384157381675429613297548478513962295468371
C9: 6 => CTR
* .2973.8148..9.123.13.8.279....129683962384157381...429.1329.5484586139722964.83.1
* PAIR B8: 5,7 COL B
B2: 5,7,4                                # reduction candidate for 5,7
B2: 5,7                                  # 14 pairs
B4: 5,7,4                                # reduction candidate for 5,7
B4: 5,7                                  # 16 pairs
* PAIR F7: 6,7 BLK 8
E9: 6,7,5                                # reduction candidate for 6,7
E9: 6,7 => SOLVED
* 529736814847951236136842795754129683962384157381675429613297548478513962295468371
E9: 5 => CTR
* .2973581487.9.123.13.8.279....129683962384157381.7.429.132975484.8613972297458361
* PAIR F7: 6,7 COL F
F6: 6,7,5                                # reduction candidate for 6,7
F6: 6,7 => CTR
* .297358148..9.123.13.8.279.5..129683962384157381...429713296548458.139.229.4.83.1
F6: 5 => SOLVED
* 529736814847951236136842795754129683962384157381675429613297548478513962295468371
* PAIR D8: 5,6 BLK 8
E9: 5,6,7                                # reduction candidate for 5,6
E9: 5,6 => SOLVED
* 529736814847951236136842795754129683962384157381675429613297548478513962295468371
E9: 7 => CTR
* .2973.8148..9.123.13.8.279....129683962384157381...429.1329.5484.851396229.4.83.1
* PAIR H9: 6,7 ROW 9
C9: 6,7,5                                # reduction candidate for 6,7
C9: 6,7 => CTR
* .297358148..9.123.13.8.279.5..129683962384157381576429.1329.54845861397229.458361
C9: 5 => SOLVED
* 529736814847951236136842795754129683962384157381675429613297548478513962295468371
E9: 6,7,5                                # reduction candidate for 6,7
E9: 6,7 => SOLVED
* 529736814847951236136842795754129683962384157381675429613297548478513962295468371
E9: 5 => CTR
* .2973581487.9.123.13.8.279....129683962384157381.7.429.132975484.8613972297458361
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-074-base-pr-000.dot
* REASONING
* DIS # C2: 5,6 => CTR => C2: 4,7
* PRF # F6: 5,6 => SOL
* DIS # F6: 7 => CTR => F6: 5,6
* DIS # C2: 5,6 => CTR => C2: 4,7
* DIS # E6: 5,6 => CTR => E6: 7
* PRF # E6: 7 => SOL
* PRF # F6: 5,6 => SOL
* DIS # F6: 7 => CTR => F6: 5,6
* DIS # C9: 6,7 => CTR => C9: 5
* PRF # C9: 5 => SOL
* PRF # C9: 5,7 => SOL
* DIS # C9: 6 => CTR => C9: 5,7
* PRF # E9: 6,7 => SOL
* DIS # E9: 5 => CTR => E9: 6,7
* DIS # F6: 6,7 => CTR => F6: 5
* PRF # F6: 5 => SOL
* PRF # E9: 5,6 => SOL
* DIS # E9: 7 => CTR => E9: 5,6
* DIS # C9: 6,7 => CTR => C9: 5
* PRF # C9: 5 => SOL
* PRF # E9: 6,7 => SOL
* DIS # E9: 5 => CTR => E9: 6,7
* CNT  22 HDP CHAINS /  34 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,A7,B8,D6,D8,F1,F7,H8,H9,I2,I3)
* .2973.8148..9.123.13.8.279....129683962384157381...429.1329.5484.8.139.229.4.83.1
* PAIR A1: 5,6 BLK 1
C2: 5,6,4,7                              # reduction candidate for 5,6
C2: 5,6 => CTR
* .2973581487.94123.1348.279..4.129683962384157381...429.1329.54845861397229.458361
C3: 5,6,4                                # reduction candidate for 5,6
C3: 5,6                                  # 16 pairs
* RESTART
* PAIR A1: 5,6 BLK 1
C3: 5,6,4                                # reduction candidate for 5,6
C3: 4 => CTR
* 6297358148579.123.13.8.279....129683962384157381...429.1329.5484.8.139.229.4.83.1
* PAIR F1: 5,6 COL F
F6: 5,6,7                                # reduction candidate for 5,6
F6: 5,6 => SOLVED
* 529736814847951236136842795754129683962384157381675429613297548478513962295468371
* DURATION: 0:00:06.953132  START: 05:16:16.031775  END: 05:16:22.984907 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-074-base-pr-001.dot
* REASONING
* DIS # C2: 5,6 => CTR => C2: 4,7
* DIS C2: 4,7 # C3: 4 => CTR => C3: 5,6
* PRF C2: 4,7 + C3: 5,6 # F6: 5,6 => SOL
* STA C2: 4,7 + C3: 5,6 + F6: 5,6
* CNT   3 HDP CHAINS /   5 HYP OPENED

Header Info

Top 500 Minimum 17 074

solution: 529736814847951236136842795754129683962384157381675429613297548478513962295468371
info: 1491     FNBHWXY  S8.f     16912

http://www.sfsudoku.com/su17ExtremeDiff500.txt from http://www.minimumsudoku.com/

Solution

position: 529736814847951236136842795754129683962384157381675429613297548478513962295468371 solved
Solution

See section Pair Reduction for the HDP chains leading to this result.

Appendix: Full HDP Chains

A1. Pair Reduction Analysis

Full list of HDP chains traversed:

* DIS # C2: 5,6 => CTR => C2: 4,7
* INC # C2: 4,7 => UNS
* INC # C3: 5,6 => UNS
* INC # E2: 5,6 => UNS
* INC # E3: 5,6 => UNS
* PRF # F6: 5,6 => SOL
* DIS # F6: 7 => CTR => F6: 5,6
* DIS # C2: 5,6 => CTR => C2: 4,7
* INC # C2: 4,7 => UNS
* INC # E2: 5,6 => UNS
* INC # C3: 5,6 => UNS
* INC # E3: 5,6 => UNS
* INC # B4: 5,7 => UNS
* INC # C4: 5,7 => UNS
* DIS # E6: 5,6 => CTR => E6: 7
* PRF # E6: 7 => SOL
* PRF # F6: 5,6 => SOL
* DIS # F6: 7 => CTR => F6: 5,6
* DIS # C9: 6,7 => CTR => C9: 5
* PRF # C9: 5 => SOL
* PRF # C9: 5,7 => SOL
* DIS # C9: 6 => CTR => C9: 5,7
* INC # B2: 5,7 => UNS
* INC # B4: 5,7 => UNS
* PRF # E9: 6,7 => SOL
* DIS # E9: 5 => CTR => E9: 6,7
* DIS # F6: 6,7 => CTR => F6: 5
* PRF # F6: 5 => SOL
* PRF # E9: 5,6 => SOL
* DIS # E9: 7 => CTR => E9: 5,6
* DIS # C9: 6,7 => CTR => C9: 5
* PRF # C9: 5 => SOL
* PRF # E9: 6,7 => SOL
* DIS # E9: 5 => CTR => E9: 6,7
* CNT  34 HDP CHAINS /  34 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C2: 5,6 => CTR => C2: 4,7
* INC C2: 4,7 # C3: 5,6 => UNS
* INC C2: 4,7 # C3: 5,6 => UNS
* DIS C2: 4,7 # C3: 4 => CTR => C3: 5,6
* PRF C2: 4,7 + C3: 5,6 # F6: 5,6 => SOL
* STA C2: 4,7 + C3: 5,6 + F6: 5,6
* CNT   5 HDP CHAINS /   5 HYP OPENED